Development of diffuse alveolar damage after initiation of Nijutsuto

Chinese traditional medicine, Nijutsuto, is used to treat patients with frozen shoulder and osteoarthritis. Herbal medicine is often linked to the development of interstitial lung disease. An 83‐year‐old Japanese man with osteoarthritis who was on Nijutsuto was admitted to our hospital with dyspnoea and severe cough after 2 weeks from initiation of Nijutsuto. A chest computed tomography scan on admission showed diffuse ground glass opacity with traction bronchiectasis. Thus, he was diagnosed with Nijutsuto‐induced interstitial lung disease, and was treated with a high dose of methylprednisolone and cyclophosphamide. However, the patient died of respiratory failure 2 weeks after admission. The patient was definitively diagnosed with diffuse alveolar damage by pathological autopsy. Nijutsuto contains Radix Scutellariae, which is considered to be the cause of interstitial lung disease. Chinese traditional medicine containing both Radix Scutellariae and Licorice should be carefully used because of its potential role in the development of diffuse alveolar damage.